Flip-chip mounting substrate and flip-chip mounting method
A solder resist and a central pad to which a central Au bump provided on a semiconductor chip is flip-chip bonded are formed on a substrate main body. In a flip-chip mounting substrate where an underfill resin is provided after the semiconductor chip is mounted, a central opening portion for exposing the central pad is formed in the solder resist, and also, an edge portion forming the central opening portion of the solder resist is partially overlapped with the outer peripheral portion of the central pad.
1. A flip-chip mounting method for flip-chip mounting an electronic element on which an Au bump is provided, the flip-chip mounting method comprising:
providing a flip-chip mounting substrate, comprising:
a substrate main body,
a connecting pad provided on the substrate main body and to which the Au bump provided on the electronic element is flip-chip bonded, and
a solder resist on the substrate main body, the solder resist having an opening portion for exposing the connecting pad, wherein an edge portion of the opening portion is partially overlapped with an outer peripheral portion of the connecting pad;
providing an electrically conductive bonding material on the connecting pad which is exposed from the opening portion formed in the solder resist of the flip-chip mounting substrate;
bonding the Au bump and the connecting pad with the bonding material so that the bonding material secures and electrically connects the Au bump and the connecting pad together and the electronic element is mounted on the flip-chip mounting substrate, said bonding material and bump cooperating to fill the opening portion in the solder resist and cover a surface of the connecting pad; and
filling a gap between the electronic element and the flip-chip mounting substrate with an underfill resin while the bump and bonding material cooperate to prevent the underfill resin from flowing into the opening portion.
2. A flip-chip mounting method for flip-chip mounting an electronic element on which an Au bump is provided, the flip-chip mounting method comprising:
providing a flip-chip mounting substrate, comprising:
a substrate main body,
a connecting pad provided on the substrate main body and to which the Au bump provided on the electronic element is flip-chip bonded, and
a solder resist on the substrate main body, the solder resist having an opening portion for exposing the connecting pad, wherein an edge portion of the opening portion is in direct contact with an outer peripheral portion of the connecting pad;
providing a bonding material on the connecting pad which is exposed from the opening portion formed in the solder resist of the flip-chip mounting substrate;
bonding the Au bump and the connecting pad via the bonding material so as to mount the electronic element on the flip-chip mounting substrate, said Au bump extending into said opening portion and said bonding material and bump cooperating to fill the opening portion in the solder resist and cover a surface of the connecting pad; and
filling a gap between the electronic element and the flip-chip mounting substrate with an underfill resin while the bump and bonding material cooperate to prevent the underfill resin from flowing into the opening portion.
3. The flip-chip mounting method as claimed in claim 1 , wherein the bonding material fills up the opening portion formed in the solder resist when the Au bump and the connecting pad are bonded.
4. The flip-chip mounting method as claimed in claim 2 , wherein the bonding material fills up the opening portion formed in the solder resist when the Au bump and the connecting pad are bonded.
5. The flip-chip mounting method as claimed in claim 2 , wherein the bonding material is conductive.
6. The flip-chip mounting method as claimed in claim 2 , wherein the bonding material secures and electrically connects the Au bump and the connecting pad together.